1. In cases of Hirschsprung's disease with aganglionic segment confined to the rectum, even severe symptoms can subside considerably at some time or other usually before the age of 20. 2. Very slight symptoms may occur in spite of considerable radiological dilatation of the colon. 3. A period--even of several years--with only slight symptoms is no assurance against later aggravation. Severe and even fatal symptoms can suddenly appear.